This invention relates to methods for reproducing a three-dimensional surface, and more particularly to methods for making surfaces for use with prosthetic devices, such as gloves resembling hands, feet, fingers, and other similar articles.
One of the original techniques for making a prosthetic surface included making a plaster cast of a human limb that could be used to manufacture an artificial one. This method of manufacture had many drawbacks, including the appearance of a line in the artificial limb corresponding to the junction between the two halves of the mold. Moreover, the ridges and depressions that normally make up the surface of the limb, such as the ones that form fingerprints, were substantially eliminated in the manufacturing process because the plaster cast was not capable of capturing all of the detail that makes up the surface.
In order to improve the appearance of the artificial limb, cosmetic gloves and the like were developed that more closely approximate the natural appearance of human skin. See, e.g., Milton et al. U.S. Pat. No. 2,657,394. The manufacture of such gloves, however, still required a process of reversing a physical mold in order to properly match the artificial limb with a natural one. Mold reversal may involve cutting the mold into parts and reattaching them in a reversed orientation, forming seams and other undesirable surface effects that must be later eliminated, or at least diminished, in the final stages of making the glove. However, the elimination of such surface effects is imperfect and usually a slow, labor intensive process.
Moreover, a patient may desire one or more superficial differences between a left and right limb (such as the appearance of a birthmark or mole). These differences can be difficult to reliably incorporate in the reversed glove because they are usually sculpted into the glove mold. However, the quality of the sculpted mold strongly depends upon the skill and artistry of the sculptor, making this process unreliable at best.
Methods for making prosthetic devices with laser and ultrasonic digitizing systems are known. See, e.g., Clynch et al. U.S. Pat. No. 5,432,703 and Walsh et al. U.S. Pat. No. 5,539,649. However, these methods do not address the difficulty of reproducing high resolution prosthetic surfaces, let alone high resolution prosthetic surfaces for residual limbs. For example, Clynch et al. was mainly concerned with producing an accurately shaped socket for reception of a residual limb in a prosthetic structure. Furthermore, Walsh et al. was concerned with providing dimensional information with regard to the relative location of the limb, skin, and bone surfaces in three-dimensional space.
Thus, it would therefore be desirable to provide methods for accurately making high resolution surfaces, especially surfaces of prosthetic devices.
It would be particularly desirable to provide methods for reliably making a prosthetic skin that matches the skin of a real counterpart limb, including any cosmetic differences or details desired by a patient.
It would also be particularly desirable to provide methods for rapidly designing and making high-resolution prosthetic surfaces, without manufacturing multiple iterations.